Automatic cut-off for intravenous equipment

ABSTRACT

A valve assembly is positioned in the drip chamber of a conventional intravenous container and includes a steel flotation ball which seals the chamber orifice when the intravenous liquid in the container is expended. A floatation plug floats above the ball and serves as a hold-down means for clamping the ball against the orifice when the fluid is almost expended. In order to prevent the ball and plug from floating to an upper portion of the drip chamber, a retaining ring is fastened near the orifice end of the chamber. The valve assembly goes into operation when the last few drops of intravenous fluid remain at the drip chamber orifice.

ilnited States Patent Urian 151 3,65,95 451 Apr. 18,1972

[54] AUTOMATIC CUT-OFF FOR INTRAVENOUS EQUIPMENT [72] Inventor: Ellen M.OBrian, 221'Bi1marsan Drive,

Biloxi, Miss. 39530 [22] Filed: May 6, 1970 21 Appl. No.: 34,998

3,105,511 10/1963 Murphy,.lr. ..137/399 3,216,419 11/1965 Scislowicz..137/399x 3,465,784 9/1969 Cofoid ..137/430x Primary Examiner-M. CaryNelson Assistant Examiner-David R. Matthews Attorney-Clarence A. OBrienand Harvey B. Jacobson [57] ABSTRACT A valve assembly is positioned inthe drip chamber'of a conventional intravenous container and includes asteel flotation ball which seals the chamber orifice when theintravenous liquid in the container is expended. A floatation plugfloats above the ball and serves as a hold-down means for clamping theball against the orifice when the fluid is almost expended. In order toprevent the ball and plug from floating to an upper portion of the dripchamber, a retaining ring is fastened near the orifice end of thechamber. The valve assembly goes into operation when the last few dropsof intravenous fluid remain at the drip chamber orifice.

5 Claims, 4 Drawing Figures Pmmmm 8 I912 .HgJ'

Fig. 4

f/len M. OBr/an INVENTOK.

AUTOMATIC CUT-OFF FOR INTRAVENOUS EQUIPMENT The present inventionrelates to intravenous apparatus and more particularly to a safetycut-off valve for terminating flow of intravenous fluids in the dripchamber of a conventional intravenous apparatus.

At the present time, the process of intravenous feed requires theattendance of a nurse during a protracted period when an intravenousprocedure is being terminated. However, often her services are moreurgently needed elsewhere. Accordingly, it would be desirable to equipconventional intravenous equipment with a suction valve assembly whichwould seal the intravenous fluid drip chamber when only a few last dropsof the fluid are all that is left.

The present invention is directed to such a cut-off valve assembly thatcan be conveniently inserted into conventional intravenous equipment.The present device is a safety apparatus which prevents the possibilityof air or harmful gases from entering a patients veins in the event thatintravenous fluid becomes expended before a nurse can properlydiscontinue the fluid flow. By using the instant device, a nurse cancare for more urgent needs and come back at a later time to terminatethe intravenous procedure. By stopping the flow of fluid from the dripchamber as soon as the last few drops are sensed in the chamber, acolumn of fluid remains in the feed line that is connected to thepatients vein. This column seals the circulatory system from unwantedair and harmful gases.

These together with other objects and advantages which will becomesubsequently apparent reside in the details of construction andoperation as more fully hereinafter described and claimed, referencebeing had to the accompanying drawings forming a part hereof, whereinlike numerals refer to like parts throughout, and in which:

FIG. 1 is an elevational view illustrating a conventional intravenousdevice equipped with the automatic cut-off suction valve assembly.

FIG. 2 is an exploded view illustrating the three components of thesuction valve assembly.

FIG. 3 is a sectional view illustrating the disposition of the valvecomponents during normal flow of intravenous fluid through the dripchamber.

FIG. 4 shows the sealing position of the valve components aftersubstantially all of the fluid has been expended from the drip chamber.

Referring to the figures and more particularly FIG. 1, a conventionalintravenous dispenser equipped with the present valve invention isgenerally indicated by reference numeral 10 and is seen to include aninverted bottle container 12 which stores the intravenous fluid 14. Theneck 16 of the bottle communicates with the usual vent 18 for producingsmooth and continuous flow to a drop chamber 20 positioned downwardlyfrom the neck of the bottle. The orifice of the drip chamber 20 mountsthe usual feed line 22 which is connected at an opposite end thereof toa needle (not shown) that is inserted into a patients vein.

Considering FIGS. 2 and 3, the components of the present suction valveassembly are seen to be three in number. The assembly is generallyindicated by reference numeral 24 and includes retaining means in theform of a split ring 26 having a gap 28 therein that allows fluid toflow freely past the ring. The peripheral outward edge of the ring 26has a number of spike-like projections 30 extending outwardly whichspace the ring from the interior wall of the drip chamber 20. Theprojections serve to increase the flow of fluid past the ring and alsoinsures the proper horizontal orientation of the ring within thechamber. A hold-down means in the form of an elastomeric plug 32normally floats in the fluid l4 and remains clear of the chamber orifice33 as long as a substantial amount of fluid is in the chamber. As seenin FIG. 2, the plug includes a disc-like base 34 extending downwardlyand inwardly to a boss-like projection 36 having a central underlyinghemispherical recess 38 therein which is adapted to reside in registrywith a steel ball 40, the latter serving as the actual seal against theupper end or inlet 41 of feed line 22. Although the ball 40 remainsclear of the line inlet 41 when a substantial quantity of fluid 14resides in the chamber, the ball will become displaced into sealingengagement with the inlet end 41 when the level of fluid falls below thelower surface of plug 32. However, prior to this situation, ring 26serves as a stop limit for the upward displacement of the plug 32 andprevents the plug from floating upwardly into an upper portion of thedrip chamber 20. Of course, since the plug 32 is restrained, the steelball 40 will likewise be restrained from floating upwardly into thechamber 20.

FIG. 4 illustrates the condition of the valve components when the lastfew drops of liquid remain in the drip chamber 20. This state of affairscauses the ball 40 to fall into sealing engagement with the inlet end 41of line 22 thereby sealing the line and causing a column of fluid toremain in the line 22 thereby sealing the patients vein from air orharmful gases. The figure clearly illustrates how the ring 26 remains inposition due to its biased engagement with the chamber wall while plug32 receives ball 40 in recess 38 and clamps the ball into sealingengagement with the inlet end 41 of line 22. Actually, a small suctionforce is exerted on the underside of the plug which enhances itshold-down capability.

If, after automatic cut-ofi as just described, additional fluid is to beintroduced into the patient, a fresh supply is introduced into theintravenous apparatus which will cause the plug 32 and ball 40 tomaintain their clear position as discussed in connection with FIG. 3.

The ring 26 and plug 32 have been particularly designed so that they donot interfere or impede the normal flow of intravenous fluid through thedrip chamber 20 and feed line 22. By way of example, the conventionalintravenous container 12 and drip chamber 20 may be of the typecurrently marketed by Abbot Laboratories, Inc.

The foregoing is considered as illustrative only of the principles ofthe invention. Further, since numerous modifications and changes willreadily occur to those skilled in the art, it is not desired to limitthe invention to the exact construction and operation shown anddescribed, and accordingly all suitable modifications and equivalentsmay be resorted to, falling within the scope of the invention asclaimed.

What is claimed as new is as follows:

1. An automatic flow cut-off assembly for intravenous equipmentcomprising a vertical drip chamber conduit of constant cross-sectionthroughout a major portion of its height, said conduit including adownwardly converging lower portion terminating in an outlet orifice, anintravenous patient feed tube connected to the orifice, normally openvalving means in the conduit responsive to the absence of intravenousfluid in the conduit for sealing the orifice, buoyant hold-down meansabove the valving means for selective downward movement into a positionclamping the valving means against the orifice when fluid is absent, andretaining means in spaced relation above said orifice for limiting theupward displacement of the hold-down means in the presence of fluidwhereby fluid is free to flow from the conduit through the orifice untila preselected minimal quantity remains at which time the orifice issealed, said hold-down means comprising an imperforate disc-like suctionplug having a downwardly directed recess therein for centrally receivingthe valving means and clamping the valving means against the dripchamber outlet orifice when fluid is absent in the conduit, said plugbeing of a cross-section less than that of the conduit at the retainingmeans to allow free flow past the upwardly displaced plug, and greaterthan that of the conduit in its valving means clamping position for asealing of the conduit in conjunction with a clamping of the valvingmeans against the orifice.

2. The assembly of claim 1 wherein the valving means is a ball having adiameter exceeding that of the drip chamber outlet orifice.

3. The assembly of claim 2 wherein the retaining means comprises a ringmember having peripherally spaced projections extending outwardlytherefrom, said projections engagcomprises a ring member havingperipherally spaced projections extending outwardly therefrom, saidprojections engaging the interior wall of the drip chamber conduit tomount and center said ring in the conduit.

1. An automatic flow cut-off assembly for intravenous equipmentcomprising a vertical drip chamber conduit of constant crosssectionthroughout a major portion of its height, said conduit including adownwardly converging lower portion terminating in an outlet orifice, anintravenous patient feed tube connected to the orifice, normally openvalving means in the conduit responsive to the absence of intravenousfluid in the conduit for sealing the orifice, buoyant hold-down meansabove the valving means for selective downward movement into a positionclamping the valving means against the orifice when fluid is absent, andretaining means in spaced relation above said orifice for limiting theupward displacement of the hold-down means in the presence of fluidwhereby fluid is free to flow from the conduit through the orifice untila preselected minimal quantity remains at which time the orifice issealed, said hold-down means comprising an imperforate disc-like suctionplug having a downwardly directed recess therein for centrally receivingthe valving means and clamping the valving means against the dripchamber outlet orifice when fluid is absent in the conduit, said plugbeing of a cross-section less than that of the conduit at the retainingmeans to allow free flow past the upwardly displaced plug, and greaterthan that of the conduit in its valving means clamping position for asealing of the conduit in conjunction with a clamping of the valvingmeans against the orifice.
 2. The assembly of claim 1 wherein thevalving means is a ball having a diameter exceeding that of the dripchamber outlet orifice.
 3. The assembly of claim 2 wherein the retainingmeans comprises a ring member having peripherally spaced projectionsextending outwardly therefrom, said projections engaging the interiorwall of the drip chamber conduit to mount and center said ring in theconduit.
 4. The assembly of claim 3 wherein said ring member is in thenature of a split ring including spaced ends defining a fluid passagetherebetween.
 5. The assembly of claim 1 wherein the retaining meanscomprises a ring member having peripherally spaced projections extendingoutwardly therefrom, said projections engaging the interior wall of thedrip chamber conduit to mount and center said ring in the conduit.